Stent device delivery system with inwardly tapering stent bed

Abstract

A stent device delivery system and method of making. The stent device delivery system includes a stent device, an outer sheath overlaying the stent device in a radially compact, delivery configuration of the stent device, and an inner catheter extending axially and radially within a lumen of the stent device. The inner catheter provides a stent bed upon which the stent device is located so that a radially inner surface of the stent device engages a radially outer surface of the stent bed. The stent bed may define an inwardly tapering profile, narrowing in radius from a distal portion of the stent device to a proximal portion of the stent device.

What is claimed is: 
     
       1. A method of making a stent device delivery system, comprising:
 loading a device into a retractable outer sheath comprising a sleeve, the retractable outer sheath having a delivery position that retains the device and a deployed position that radially frees the device; 
 positioning an inner catheter radially and axially within a lumen of the device, wherein the inner catheter comprises an inwardly tapered bed; and 
 cold-drawing the sleeve:
 to reduce a diameter of the sleeve; 
 to squeeze the device from an expanded configuration into a reduced delivery configuration; and 
 to engage a radially inner surface of the device with a radially outer surface of the inwardly tapered bed. 
 
 
     
     
       2. The method of  claim 1 , further comprising folding the sleeve onto itself to form an outer sheath inner layer, an outer sheath outer layer, and a distal fold-over portion. 
     
     
       3. The method of  claim 2 , wherein the inwardly tapered bed tapers from a distal major diameter to a proximal minor diameter. 
     
     
       4. The method of  claim 1 , further comprising providing a pullback system having an inner and an outer layer portion laminated together. 
     
     
       5. The method of  claim 1 , wherein the sleeve comprises an inner and an outer layer portion to form a rolling outer sheath. 
     
     
       6. The method of  claim 2 , wherein relative movement of the inner and the outer layer causes movement of the distal fold-over portion. 
     
     
       7. The method  claim 6 , wherein folding the sleeve comprises positioning a tapered mandrel radially and axially within the sleeve abutting an end of the device. 
     
     
       8. The method of  claim 7 , wherein the tapered mandrel comprises a taper that matches a taper of the inwardly tapered bed. 
     
     
       9. The method of  claim 8 , wherein the cold-drawing step further comprises drawing the sleeve onto the tapered mandrel yielding a cold drawn portion overlaying the device and overlaying the tapered mandrel. 
     
     
       10. The method of  claim 9 , wherein folding the sleeve further comprises folding the cold drawn portion overlaying the tapered mandrel over the cold drawn portion overlaying the device. 
     
     
       11. The method of  claim 10 , wherein the sleeve is polymeric. 
     
     
       12. The method of  claim 11 , further comprising a step of providing an outer catheter around an outer sheath end and extending distally to the device. 
     
     
       13. The method of  claim 12 , wherein the inwardly tapered bed comprises a layer on the inner catheter. 
     
     
       14. The method of  claim 13 , wherein the inwardly tapered bed comprises a tacky material that radially and axially holds the device and the device peels away from the tacky material during expansion. 
     
     
       15. The method of  claim 14 , wherein the inwardly tapered bed tapers stepwise. 
     
     
       16. The method of  claim 15 , wherein the inwardly tapered bed is axially continuous. 
     
     
       17. The method of  claim 15 , wherein the inwardly tapered bed comprises a plurality of axially separated bands. 
     
     
       18. The method of  claim 17 , wherein the axially separated bands define a stepwise, proximally reducing bed diameter. 
     
     
       19. The method of  claim 18 , wherein the inwardly tapered bed is compressible and the device is embedded in the inwardly tapered bed. 
     
     
       20. A method of making a stent device delivery system, comprising:
 loading a device into a retractable outer sheath comprising a polymeric sleeve, the retractable outer sheath having a delivery position that retains the device and a deployed position that radially frees the device; 
 positioning an inner catheter radially and axially within a lumen of the device, wherein the inner catheter comprises an axially continuous, inwardly tapered bed that engages the device, tapers from a distal major diameter to a proximal minor diameter, and forms a layer on the inner catheter wherein the inwardly tapered bed comprises a compressible, tacky material that radially and axially holds the device and the device peels away from the tacky material during expansion; 
 positioning a tapered mandrel, which includes a taper that matches a taper of the inwardly tapered bed, radially and axially within the polymeric sleeve abutting a device end; providing a pullback system having an inner and an outer layer portion laminated together; 
 cold-drawing the polymeric sleeve onto the tapered mandrel yielding a cold drawn portion overlaying the device and overlaying the tapered mandrel:
 to reduce a diameter of the polymeric sleeve; 
 to squeeze the device from an expanded configuration into a reduced delivery configuration; and 
 to engage a radially inner surface of the device with a radially outer surface of the inwardly tapered bed; 
 
 folding the cold drawn portion overlaying the tapered mandrel onto the cold drawn portion overlaying the device to form a rolling outer sheath with an outer sheath inner layer, an outer sheath outer layer, and a distal fold-over portion disposed wherein inner and outer layer movement causes fold-over portion movement; and 
 providing an outer catheter around an outer sheath end and extending distally to the device.